Low-energy electron collisions with sulfur hexafluoride, SF6

Abstract

We report calculated cross sections for elastic and electronically inelastic collisions of low-energy electrons with sulfur hexafluoride, SF 6 . Elastic cross sections are computed within the fixed-nuclei approximation, with polarization effects incorporated. Inelastic cross sections for nine low-lying states are computed in a few-channel approximation. We compare our cross sections to previous experimental and computational results where possible.

Electron impact scattering by SF6 molecule over an extensive energy range

“…The threshold of vertical excitation energies for both triplet states 3A g and 3B 1g are 11.594 eV and 11.597 eV, respectively, showing agreement with the rst electronic transition at 11.19 eV of Winstead and McKoy. 25 However, calculation of the rst excitation energy in the current work displays good agreement with the rst strong continuum reported at 11.6 eV in the absorption 59 There is also a prominent feature at around 17 eV in the excitation curves for 1A g , which coincides with the resonance due to 1B 1g reported earlier.…”

“…The DCS for 2.7 eV impact energy that we calculated shows a similar shape to those obtained experimentally by Rohr 17 and Cho et al, 18 although not all the data are consistent with each other. At 5, 7, and 10 eV the DCS matches quite well with the calculation of Winstead and McKoy 25 and experiments of Rohr 17 and Trajmar et al 15 The humps in the DCS are shied backward for higher impact energies and follow the similar trend of the measurements by Rohr 17 and Cho et al 18 for most of the energy levels.…”

“…45 The rst electronic excitation energy for SF 6 was found to be 11.5942 eV, showing good agreement with the calculated value 11.19. 25 These target properties, along with available results from the literature, are given in Table 2.…”

Resolving the forbidden band of SF6

“…2,5 Likewise, electronmolecule collisional effects, important for the technological insulation applications of SF 6 , are affected by vibrational and polarization properties. 6 SF 6 has several different technological applications, with its main use in the electrical industry because of its insulating properties 7 but it is also used in aluminum and magnesium foundries, the electronic semi-conductor industry and as an inert carrier gas in chemical reactions and medicine. As a result, it is now present in the atmosphere and, although at a relatively low concentration, it has been steadily growing.…”

Electron scattering by sulfur tetrafluoride (SF4) molecules

“…Both TCSs exhibit distinct maxima near 12 eV and above minimum near 20 eV they have very broad enhancement centred around 40 eV with some weak structure discernible near 25 eV. The maximum at 12 eV and the structure near 25 eV were found to be, for SF 6 , mainly atomic in character and were associated with the central sulfur atom (Dehmer et al 1978, Gyemant et al 1980, Gianturco et al 1995, Winstead and McKoy 2004. Such close similarity in the shape of TCS for SF 4 and SF 6 may indicate the same origin of the structures visible in the compared TCS energy dependences.…”